Method and apparatus for manufacturing metallic strip



Marci; 4, 1941;

'C. G. HERBERT METHOD AND APPARATUS FOR MANUFACTURING METALLIC STRI'?Filed Feb. 16, 1939 2 Sheets-Sheet 1 BY /QW ATTORNEY Mimih 1941'- c. G;HERBERT 7 2,234,153 I METHOD AND APPARATUS FOR MANUFACTURING METALLICSTRIP Filed Feb. 16, 1939 2 Sheets-Sheet '2 INVENTOR ATTORNEY PatentedMar. 4, 1941 UNITED STATES METHOD AND APPARATUS FOR MANUFAC- TURINGMETALLIC STRIP Clarence George Herbert, Cleveland, Ohio, assignor toUnited Engineering and Foundry Company, Pittsburgh, Pa.

Application February 16, 1939, Serial No. 256,711

16 Claims.

This invention relates to the cleaning of metal sheets, strips, platesand the like, and more particularly to a method and apparatus forremoving lubricants and other foreign matter accumulating on thesurfaces of such material during the cold rolling thereof.

In the cold rolling of sheets (used herein as a generic term for sheets,strips, plates and like material) it is the customary practice to applycooling and lubricating liquids to the surfaces of the sheets and themill rolls to reduce the rolling friction and the heating of the sheetsand rolls, with resulting improvement in the product as well as economyin rolling. Due to this practice, however, the finished sheets emergefrom the mill covered with an oily or greasy film which usually, forsatisfactory results, has to be removed before the sheets are annealed,coated, galvanized or otherwise treated as such treatments all require aclean oil-free surface.

Heretofore it has been the customary procedure to remove the lubricantand dirt adhering to the sheets after completion of the rollingoperation by submitting the rolled product to a cleansing operationin.which it is subjected to an acid or alkaline bath followed byrinsing, scrubbing and drying. In addition to the extra time required tocarry out such an operation, cumbersome and expensive equipment is used,all of which adds considerably to the cost of production. Also, thecleaning solution sometimes damages the surface of the sheet.

It is among the objects of this invention to cleanse such sheets withoutthe use of expensive and cumbersome equipment, without requiring anytime for it in addition to the rolling time, and without injuring thefinish of the sheets. More specific objects are to provide a method andapparatus for cleaning a sheet while it is passing through a coldrolling mill, which does not interfere with the rolling operation, whichcleans the sheet before it passes through the last mill stand, which iseconomical and easy to operate, and

which materially reduces the cost of cleaning suchsheets.

The preferred embodiment of the invention is illustrated in theaccompanying drawings in,

continuous cold strip mill just prior to beingwound into a coil 20. Thelast stand includes working rolls 8 and I0 and backing rolls l6 and 18.It is a feature of this invention that the strip is cleaned while it isbeing rolled so that coil 20 will be formed from clean strip ready to beannealed or otherwise treated. The cleaning occurs before the strippasses through the last stand so that it will not injure the finalfinish imparted to the strip by the rolls.

Accordingly, mounted in any suitable manner transversely above the stripbetween the last two roll stands is a header 26 from which a pluralityor spray nozzles 22, independently controlled by valves 26, extenddownwardly to within a short distance of the strip. This headerisconnected by a pipe 28 to the bottom of a tank 30 mounted in anyconvenient location. The desired cleansin liquid 32 is supplied to thetank in controlled quantities through a'supply pipe 33 from a-suit ablesource of supply. To keep the liquid under the desired pressure so thatit will spray the strip when nozzle valves 24 are opened, the top of thetank is connected by a pipe 60, shut-off valve 42 and pressure controldevice 44 with a tank 48 containing a pressure fluid, such as compressedair, fed in by a compressor pump 41. The liquid in tank 30 may beagitated continuously or from time to time by supplying a compressedfluid to the liquid body through a vertical perforated pipe 3% immersedtherein and connected through shutoff valve 38 to a source of fluidunder pressure. The liquid in this tank is maintained at a suitabletemperature for best efilciency by any convenient controlled heatingdevice,'such as themstat-controlled gas burners 38 beneath the tank.

The liquid that is used to remove oil and grease from the metal strip ispreferably an alkaline solution, such as Sunesco, a solution of sodaash, or any other solution having a suitable saponify ing ordisintegratingefiect upon oil. Some of the solution sprayed on the topof the strip flows down over its edges and is caught in an open tank 52mounted immediately below the strip and extending from behind the spraynozzles to a point close to working rolls 8 and iii of the last stand.The cleansing liquid in the tank is applied to'the lower surface of thestrip by a rotatable applicator, such as a wiper 50 journaled in thesides of this tank. This roller is partially submerged in the liquid inthe tank, but its top engages the bottom of the strip. The roller may berotated by frictional engagementwith the strip, or by positive drivingmeans. Of course, rotary brushes or even spray nozzles may besubstituted for the wiper roller. The liquid in tank 52 may be kept at auniform temperature by gas burners 54 or any other heating means.

Extending from pipe 28 are branch conduits 56 terminating in horizontalheaders 51 adjacent backing rolls l6 and I8. Each of these headers isprovided with a plurality ofspray nozzles 58 directed toward theadjacent backing roll for spraying the cleansing liquid -32 thereon.This liquid cuts from the surfaces of the backing rolls the oilysolution picked up by the working rolls from the strip'and imparted tothe backing rolls.

To'further clean the rolls'of oil and foreign matter and to minimizetheir tendency to remove the oil and solid or undissolved particles fromthe strip, the backing rolls are sprayed with a light hydrocarbon,preferably kerosene. This is done by spray nozzles 84 directed at thebacking rolls and connected by headers 82 and pipes 80 to an overheadtank 6| containing the kerosene.

Another feature of this invention is that undissolved particles, as wellas the removed film of oil, are prevented to a large extent from beingreturned by the rolls to the strip. Accordingly, bearing against therolls are wiping members that extend longitudinally of 'the rolls. Thewipers 8i for lower roll [8 are biased toward it and are also removabletherefrom by means of fluid pressure motors 82. Atrough-like receptacle83 is disposed below the bottom roll for catching the liquid and solidmatter flowing from the ends of the wipers and the body of the rollitself.

Two similar wipers 66 engage the top roll at diametrically oppositepoints where they are supported by theupper portions of splash guards 61that extend downwardly and part way under the top roll. Each of theseguards is provided with a, drain pipe and is for the same purpose asthebottom receptacle as well as for preventing the top rol-l from drippingonto the strip. The lower endoi' the guard on the delivery side of therolls carries another wiper 68a close to working roll 8 to aid inpreventing the foreign matter on the top roll from being carried back tothe working roll. Each of these guards is pivoted at its upper end to asupport 88' which carries a fluid pressure motor ii. The piston of thismotor is pivotally connected to a link 14 which in turn is rigidlyconnected to the upper portion of the guard. These motors cause theguards to be swung toward and away from the upper roll, and also biasthe wipers against the roll while the cleaning apparatusis being used.The various wipers distribute the cleansing liquid and the keroseneevenly over the surfaces of the backing rolls, and they also arrest andsegregate the undissolved contaminating matter adhering to the rolls,thereby preventing it from being returned. to the strip and rolled intoit.

The small amount of foreign matter. such as liquid and solid particles,that passes between the working rolls of the last stand with the stripis blown therefrom by fluid under pressure. For this purpose a pair ofblow nozzles Si is mounted above the strip and another pair 82 below itwith their outlets closely adjacent the working rolls where they aredirected outwardly toward the edges ofthe strip in order to remove theforeign matter therefrom by the combined action of pressure and suction,as shown in Fig. 2. The inlet ends of these nozzles are disposedtransversely of the strip and are telescopically' and rotatably' mountedin clamps 83 attached to suitable supports 94. Set screws 88, threadedin these clamps and bearing against the nozzles, hold them in anyposition to which they may be adjusted vertically or transversely of thestrip, the latter adjustment being for strips of different widths. Thesenozzles are connected by pipes 81 to a suitable source of fluid underpressure, such as compressed air.

It will thus be seen that the apparatus contemplated by this inventionis relatively simple and inexpensive and requires butlittle space. Twomaior 1 advantages are that the strip is cleaned during the rollingoperation, so that no additional time is required for a cleaningoperation, and the cleaning is followed, instead of being preceded, by afinishing pass through the last mill stand, whereby the final finishimparted to the strip by the rolls can not be injured by the chemical inthe cleaning liquid.

According to the provisions of the patent statuztes I have explained theprinciple and mode of operation of my invention, and have illustratedand described what I now consider to represent its best embodiment.However, I desire to have it understood that, within the scope of theapj pended'claims, the invention may be practiced otherwise than asspecifically illustrated and described.

Iclaim: I

1. The method of cleaning metal sheets comprising applying a cleansingliquid to the surfaces of a sheet during cold rolling thereof and beforethey enter the last stand of the rolling mill, wiping the rolls of saidstand to remove from their surfaces undissolved contaminating matterreceived by them from the sheet, and removing from the sheet as itleaves said stand substantially all of the foreign matter adheringthereto.

2. The method of cleaning metal sheets comprising applying a cleansingliquid to the surfaces of a sheet during cold rolling thereof and beforethey enter the last stand of the rolling mill, applying a cleaningliquid to the rolls of said stand, wiping the surfaces of said rolls toremove undissolved contaminating matter received by them from the sheet,and removing from the sheet as it leaves said stand substantially all ofthe foreign matter adhering thereto.

3. The method of cleaning metal sheets comprising applying a. cleansingliquid to the surfaces of a sheet during cold rolling thereof and beforethey enter the last stand of the rolling mill, applying a cleansingliquid to the mils of said stand, wiping the. surfaces of said rolls toremove undissolved contaminating matter received by them from the sheet,and directing fluid under pressure against the surfaces of the sheet asit leaves said stand to remove therefrom substantially all foreignmatter still adhering to it.

4. The method of cleansing-metal sheets comprising applying an oil andgrease solvent to the surfaces of a moving sheet between the last twostands of a cold rolling mill, applying a light hydrocarbon to the rollsof the last stand, wiping the surfaces of said rolls to removeundissolved contaminating matter received by them from the sheet, andremoving from the sheet as it leaves said last stand substantially allof the foreign matter adhering thereto. 7

5. The method of cleansing metal sheets comprising applying an alkalinesolution reacting mill, applying said solution and kerosene to the rollsof the last stand, wiping the surfaces of said rolls to removeundissolved contaminating matter received by them from the sheet, anddirecting streams of fluid under pressure against the sheet as it leavessaid last stand to remove therefrom substantially all foreign matterstill adhering to it.

6. Sheet cleaning apparatus comprising means for applying a cleansingliquid to the surfaces of a moving sheet on the entry side of the laststand of a cold rolling mill through which the sheet is passing, meansfor wiping the rolls of said stand to remove from their surfacesundissolved contaminating matter received by them from the sheet, andmeans for removing from the sheet as it leaves said stand substantiallyall of the foreign matter adhering thereto.

7. Sheet cleaning apparatus comprising means for applying a cleansingliquid to the surfaces of a moving sheet on the entry side of the laststand of a cold rolling mill through which the sheet is passing, meansfor applying a cleansing liquid to the rolls of said stand, means forwiping the surfaces of said rolls to remove undissolved contaminatingmatter received by them from thesheet, and means for removing from thesheet as it leaves said stand substantially all of the foreign matteradhering thereto.

8. Sheet cleaning apparatus comprising means for applying a cleansingliquid to the surfaces of a moving sheet on the entry side of thelaststand of a cold rolling mill through which the sheet is passing,means for applying a cleansing liquid to the rolls of said stand,means'for wiping the surfaces of said rolls to remove undissolvedcontaminating matter received by them from the sheet, and means fordirecting fluid under pressure against the surfaces of the sheet-as itleaves said stand to remove therefrom substantially all foreign matterstill adhering to it.

9. Sheet cleaning apparatus comprising means for applying a cleansingliquid to the surfaces of a moving sheet on the entry side of the laststand of a cold rolling mill through which the sheet is passing, meansfor applying saidliquid to the rolls of said stand, means for applying alight hydrocarbon to said rolls, means for wiping the surfaces of saidrolls to remove undissolved contaminating matter received by them fromthe sheet, and means for removing from the sheet as it leaves said standsubstantially all of the foreign matter adhering thereto.

10. Sheet cleaning apparatus comprising means for applying a cleansingliquid to the surfaces of a'moving sheet between the last two stands ofa cold rolling mill, means for applying said liquid to the rolls of thelast stand, means for applying a light hydrocarbon to said stand, wipersengaging the surfaces of said rolls for removing undissolvedcontaminating matter received by them from the sheet, nozzles directedtoward the upper and lower surfaces of the sheet on the delivery side ofsaid last stand, and means for supplying fluid under pressure to saidnozzles.

11. Sheet cleaning apparatus comprising a plurality of spray nozzlesdisposed .transversely of the upper surface of a metal sheet between thelast two stands of a cold rolling mill, means for conducting a cleansingliquid to said nozzles, a tank mounted below said sheet betweensaid'stands, a wiping roll journaled on a horizontal axis and adapted tocarry cleansing liquid out of said tank and apply it to the lowersurface of the sheet, means for applying a cleansing liquid to the rollsof the last stand, wipers engaging the surfaces of said rolls forremoving undissolved contaminated matter received by them from thesheet, nozzles directed toward the upper and lower surfaces of the sheeton the delivery side of said last stand, and means for supplying fluidunder pressure to said nozzle.

12. A sheet cleaning apparatus comprising a plurality of spray nozzlesdisposed transversely of a metal sheet adjacent the delivery side of thenext to the last stand of a continuous cold rolling mill, a tank, aconduit connecting the tank with the nozzles, means for supplying acleansing liquid to said tank, means for applying pressure to the liquidin the tank, means for agitating the liquid in the tank, means forapplying a cleansing liquid to the lower surface of said sheet adjacentthe delivery side of said next to the last stand, means for applying a.cleansing liquid to the rolls of the last stand, means for continuouslywiping the rolls of said stand, and means for removing from the sheet asit leaves said last stand substantially all of the foreign matteradhering thereto.

13. A sheet'cleaning apparatus comprising a plurality of spray nozzlesdisposed transversely of a metal sheet adjacent the delivery side of thenext to the last stand of a continuous cold rolling mill, a tank, aconduit connecting the tank with the nozzles, means for supplying acleansing liquid to said tank, means for applying pressure to the liquidin the tank, means for conducting a fluid under pressure into the liquidin said tank for agitating it, means for applying a cleansing liquid tothe lower surface of said sheet adjacent the delivery side of said nextto the last stand, means for applying a cleansing liquid to the rolls ofthe last stand, means for continuously wiping the rolls of said stand,and means for removing from the sheet as it leaves said last standsubstantially all of the foreign matter adhering thereto. v

14. Sheet cleaning apparatus comprising a plurality of nozzles disposedtransversely of the upper surface of a sheet adjacent the delivery sideof the next to the last stand of a cold rolling mill, a conduitconnected to said nozzles, means for supplying a cleansing liquid tosaid conduit, nozzles disposed longitudinally of the upper and lowerrolls of the last stand of said mill, branch conduits leading from saidconduit to said last-mentioned nozzles, means for applying a cleansingliquid to the lower surface of said sheet between said last two stands,adjustable wipers engaging the surfaces of said rolls, and means fordirecting fluid under pressure against the surfaces ,of'said sheet as itemerges from said laststand.

15. Sheet cleaning apparatus comprising means for applying a cleansingliquid to the surface of a moving sheet on the entry side of the laststand of a cold rolling mill through which thesheetis passing, wipermembers extending longitudinally of the rolls of said stand and engagingtheir surfaces, receptacles mounted below said rolls for receivingmatter removed from the rolls by said wipers, and means forremoving fromthe sheet as it leaves said stand substantially all of the foreignmatter still adhering to it.

16. Sheet cleaning apparatus comprising means for applying a cleansingliquid to the surface of a moving sheet on the entry side of the laststand of a cold rolling mill through which the sheet is passing, wipingmembers extending longitudinally of the rolls of said stand and engagingtheir surfaces, fluid pressure actuated means connected to said wipersfor biasing them against the rolls,

, means supporting the wipers engaging the upper roll for receivingforeign matter removed from said roll by the wipers, and means for.removing from the sheet as it leaves said stand substantially all ofthe foreign matter adhering thereto.

CLARENCE GEORGE HERBERT.

